FFmpeg/libavcodec/c93.c
Stefano Sabatini 72415b2adb Define AVMediaType enum, and use it instead of enum CodecType, which
is deprecated and will be dropped at the next major bump.

Originally committed as revision 22735 to svn://svn.ffmpeg.org/ffmpeg/trunk
2010-03-30 23:30:55 +00:00

257 lines
7.7 KiB
C

/*
* Interplay C93 video decoder
* Copyright (c) 2007 Anssi Hannula <anssi.hannula@gmail.com>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "avcodec.h"
#include "bytestream.h"
typedef struct {
AVFrame pictures[2];
int currentpic;
} C93DecoderContext;
typedef enum {
C93_8X8_FROM_PREV = 0x02,
C93_4X4_FROM_PREV = 0x06,
C93_4X4_FROM_CURR = 0x07,
C93_8X8_2COLOR = 0x08,
C93_4X4_2COLOR = 0x0A,
C93_4X4_4COLOR_GRP = 0x0B,
C93_4X4_4COLOR = 0x0D,
C93_NOOP = 0x0E,
C93_8X8_INTRA = 0x0F,
} C93BlockType;
#define WIDTH 320
#define HEIGHT 192
#define C93_HAS_PALETTE 0x01
#define C93_FIRST_FRAME 0x02
static av_cold int decode_init(AVCodecContext *avctx)
{
avctx->pix_fmt = PIX_FMT_PAL8;
return 0;
}
static av_cold int decode_end(AVCodecContext *avctx)
{
C93DecoderContext * const c93 = avctx->priv_data;
if (c93->pictures[0].data[0])
avctx->release_buffer(avctx, &c93->pictures[0]);
if (c93->pictures[1].data[0])
avctx->release_buffer(avctx, &c93->pictures[1]);
return 0;
}
static inline int copy_block(AVCodecContext *avctx, uint8_t *to,
uint8_t *from, int offset, int height, int stride)
{
int i;
int width = height;
int from_x = offset % WIDTH;
int from_y = offset / WIDTH;
int overflow = from_x + width - WIDTH;
if (!from) {
/* silently ignoring predictive blocks in first frame */
return 0;
}
if (from_y + height > HEIGHT) {
av_log(avctx, AV_LOG_ERROR, "invalid offset %d during C93 decoding\n",
offset);
return -1;
}
if (overflow > 0) {
width -= overflow;
for (i = 0; i < height; i++) {
memcpy(&to[i*stride+width], &from[(from_y+i)*stride], overflow);
}
}
for (i = 0; i < height; i++) {
memcpy(&to[i*stride], &from[(from_y+i)*stride+from_x], width);
}
return 0;
}
static inline void draw_n_color(uint8_t *out, int stride, int width,
int height, int bpp, uint8_t cols[4], uint8_t grps[4], uint32_t col)
{
int x, y;
for (y = 0; y < height; y++) {
if (grps)
cols[0] = grps[3 * (y >> 1)];
for (x = 0; x < width; x++) {
if (grps)
cols[1]= grps[(x >> 1) + 1];
out[x + y*stride] = cols[col & ((1 << bpp) - 1)];
col >>= bpp;
}
}
}
static int decode_frame(AVCodecContext *avctx, void *data,
int *data_size, AVPacket *avpkt)
{
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
C93DecoderContext * const c93 = avctx->priv_data;
AVFrame * const newpic = &c93->pictures[c93->currentpic];
AVFrame * const oldpic = &c93->pictures[c93->currentpic^1];
AVFrame *picture = data;
uint8_t *out;
int stride, i, x, y, bt = 0;
c93->currentpic ^= 1;
newpic->reference = 1;
newpic->buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE |
FF_BUFFER_HINTS_REUSABLE | FF_BUFFER_HINTS_READABLE;
if (avctx->reget_buffer(avctx, newpic)) {
av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
return -1;
}
stride = newpic->linesize[0];
if (buf[0] & C93_FIRST_FRAME) {
newpic->pict_type = FF_I_TYPE;
newpic->key_frame = 1;
} else {
newpic->pict_type = FF_P_TYPE;
newpic->key_frame = 0;
}
if (*buf++ & C93_HAS_PALETTE) {
uint32_t *palette = (uint32_t *) newpic->data[1];
const uint8_t *palbuf = buf + buf_size - 768 - 1;
for (i = 0; i < 256; i++) {
palette[i] = bytestream_get_be24(&palbuf);
}
} else {
if (oldpic->data[1])
memcpy(newpic->data[1], oldpic->data[1], 256 * 4);
}
for (y = 0; y < HEIGHT; y += 8) {
out = newpic->data[0] + y * stride;
for (x = 0; x < WIDTH; x += 8) {
uint8_t *copy_from = oldpic->data[0];
unsigned int offset, j;
uint8_t cols[4], grps[4];
C93BlockType block_type;
if (!bt)
bt = *buf++;
block_type= bt & 0x0F;
switch (block_type) {
case C93_8X8_FROM_PREV:
offset = bytestream_get_le16(&buf);
if (copy_block(avctx, out, copy_from, offset, 8, stride))
return -1;
break;
case C93_4X4_FROM_CURR:
copy_from = newpic->data[0];
case C93_4X4_FROM_PREV:
for (j = 0; j < 8; j += 4) {
for (i = 0; i < 8; i += 4) {
offset = bytestream_get_le16(&buf);
if (copy_block(avctx, &out[j*stride+i],
copy_from, offset, 4, stride))
return -1;
}
}
break;
case C93_8X8_2COLOR:
bytestream_get_buffer(&buf, cols, 2);
for (i = 0; i < 8; i++) {
draw_n_color(out + i*stride, stride, 8, 1, 1, cols,
NULL, *buf++);
}
break;
case C93_4X4_2COLOR:
case C93_4X4_4COLOR:
case C93_4X4_4COLOR_GRP:
for (j = 0; j < 8; j += 4) {
for (i = 0; i < 8; i += 4) {
if (block_type == C93_4X4_2COLOR) {
bytestream_get_buffer(&buf, cols, 2);
draw_n_color(out + i + j*stride, stride, 4, 4,
1, cols, NULL, bytestream_get_le16(&buf));
} else if (block_type == C93_4X4_4COLOR) {
bytestream_get_buffer(&buf, cols, 4);
draw_n_color(out + i + j*stride, stride, 4, 4,
2, cols, NULL, bytestream_get_le32(&buf));
} else {
bytestream_get_buffer(&buf, grps, 4);
draw_n_color(out + i + j*stride, stride, 4, 4,
1, cols, grps, bytestream_get_le16(&buf));
}
}
}
break;
case C93_NOOP:
break;
case C93_8X8_INTRA:
for (j = 0; j < 8; j++)
bytestream_get_buffer(&buf, out + j*stride, 8);
break;
default:
av_log(avctx, AV_LOG_ERROR, "unexpected type %x at %dx%d\n",
block_type, x, y);
return -1;
}
bt >>= 4;
out += 8;
}
}
*picture = *newpic;
*data_size = sizeof(AVFrame);
return buf_size;
}
AVCodec c93_decoder = {
"c93",
AVMEDIA_TYPE_VIDEO,
CODEC_ID_C93,
sizeof(C93DecoderContext),
decode_init,
NULL,
decode_end,
decode_frame,
CODEC_CAP_DR1,
.long_name = NULL_IF_CONFIG_SMALL("Interplay C93"),
};